This invention relates to the use of industrial gases, such as nitrogen, in the operation of a multi-faceted industrial plant. The invention is especially useful in, but is not necessarily limited to, the manufacture of products for use in the fields of biotechnology, medicine, or health care.
A typical manufacturer of products in the biotechnology field may need to conduct a variety of processes in the same facility. Such processes may include deoxygenation, freezing, aerobic fermentation, palletizing, freeze drying, and inerting and blanketing. It may also be necessary to provide instrument air, i.e. a gas which can be safely and reliably used for operating instruments, such as pneumatic valves, in various processes. Such a plant may also require the ability to pulverize drug products, and to mix a highly viscous product into one of low viscosity.
In the prior art, some of the above functions may be performed with industrial gases, typically provided in compressed gas cylinders. Other functions, such as freezing and freeze drying, may be performed with compressors and conventional mechanical freezing techniques. Some of these components require electric power to operate. One object of the present invention is to reduce the amount of electric power required, and to operate a variety of components in a plant with a cryogenic liquid taken from a single source.
The following is a more detailed summary of various functions which may be performed in a facility for making products relating to the biotechnology and/or pharmaceutical industries. The following descriptions allude to the advantages that may be enjoyed by substituting industrial gases or cryogenic liquids for the mechanical or electrical means of performing the respective tasks.
1) Deoxygenation
Oxygen is removed from a solution by the introduction of nitrogen or argon. Typically, the nitrogen or argon is supplied in a lancing technique, using gas provided in cylinders. The choice of gas depends on the density and viscosity of the solution being treated. The selection of gas affects the time required for deoxygenation, and also affects the final oxygen concentration in the product. Gas supplied from cylinders is more expensive than gas provided in bulk form, so care must be taken in monitoring the quantity of gas used.
2) Freezing and Freeze-Drying
It is often necessary to freeze products, or to perform the process of freeze drying (lyophilization). Such steps are typically performed by conventional refrigeration systems, which require electricity, and which have moving parts requiring substantial maintenance. Conventional freezing has the disadvantage that an electrical power failure can shut the freezer down. Also, there is a practical limit to how much cooling can be done to a given quantity of cooling air, using conventional methods.
3) Aerobic Fermentation
The process of aerobic fermentation is probably the most widely used process in the biotechnology and pharmaceutical industries. Fermentation relies on microorganisms to produce a desired product, as a cost effective alternative to a more expensive synthetic manufacturing method. Most prior art aerobic fermenters use air compressors to supply air to the fermenters, so as to meet the oxygen required by the microorganisms in the fermentation process. In the event of an electrical power failure, the fermentation unit will need to be shut down, and may cause the operator to lose expensive batches of fermentation medium.
4) Palletizing
In a manufacturing process in the biotechnology field, mechanical or other methods are used to palletize drugs or other products.
5) Product Freezing
In the biotechnology field, it is known to freeze a diagnostic product, or a pharmaceutical product, provided in vials arranged on a tray. The tray of vials is carried to a mechanical freezer and secured in the freezer prior to closing a door. This activity can become a safety issue, as workers must carry heavy loads into and out of the freezer, causing possible back injuries. Also, the frequent opening and closing of the freezer door causes a significant delay in the freezing process. A failure of electrical power also causes a significant interruption to this process.
6) Inerting and Blanketing
A typical arrangement for inerting uses a bank of cylinders connected to a manifold, for supplying gases such as nitrogen and argon. Since the gas comes into contact with the finished product, the quality of the inerting medium is critical. A failure of electrical power can shut down the air compressors, causing instrumentation to cease operation, and causing failure of the entire inerting and blanketing process.
7) Instrument Air for Process Control
It is common, in the prior art, to use air compressors to provide instrumentation air to power various components, such as pneumatically operated valves. A failure of electrical power can easily cause a major interruption in the operation of the process.
8) Pulverizing of Drug Products
In many cases, it is necessary to pulverize a pharmaceutical product. Conventional mechanical pulverizing methods may change the quality of the finished product. In particular, the heat generated by mechanical pulverization may increase the temperature of the product, causing the loss of low-boiling hydrocarbons, and undesirably changing the quality of the product. Such problems are not encountered with cryogenic grinding. Similar considerations apply where it is desired to mix a highly viscous product into a product of lower viscosity, such as in mixing fat with protein.
The present invention provides an integrated system and method, wherein it is possible to use an industrial gas, such as nitrogen, coming from a single source, to operate a plurality of units in a facility. The invention also includes several novel subsystems suitable for use in an integrated facility which manufactures biotechnological or pharmaceutical products.